In patent citation 1 listed below, there is disclosed a structure where, when installing a roof trim (ceiling material) in a vehicle body, locking pieces disposed projecting on the roof trim are provisionally placed on trim provisional holding flanges (receiving portions) disposed projecting on center pillar portions.
In patent citation 2 listed below, there is disclosed a structure where, by provisionally fastening provisional fastening clips disposed separately from accessories on a roof trim to provisional fastening receiving portions formed on a ceiling surface of a vehicle body, workability when installing the roof trim is improved.
In patent citation 3 listed below, there is disclosed a structure where a molded ceiling is caught and provisionally placed in cutout holes (receiving portions) disposed in side impact shock absorbing ribs disposed along roof sides.
In patent citation 4 listed below, there is disclosed a structure where ducts having integrally molded provisional placement claws are integrally disposed on a reverse surface of a ceiling material and the provisional placement claws are provisionally placed utilizing placement receiving portions disposed on attachment brackets of assist grips.    Patent Citation 1: Japanese Patent Application Laid-Open (JP-A) No. H11-001147    Patent Citation 2: JP-A No. 2001-206158    Patent Citation 3: JP-A No. 2003-137038    Patent Citation 4: JP-A No. 2006-256375